Bifocal lens.



JEDWIN R. TALLEY, OF ALGONA, IOWA.

BIFOCAL LJENS.

Speciflcation of Letters Patent.

Applicat ion filed August 28, 1914. Serial N0. 859,043.

T0 all uh 0m z't m ay concern Be 1't known that I, EDWIN R. 'IAL .LEY a citizen 0f the United States of Amenca, re-

siding at Algona, in the county at Kossut'h' and Stute of Iowa, have invented certain new und useful Improvements in Bifocz xl lbenses, 0f Wl1ich t'he following is a spec1- fication. 1

This invention relates to'new and useful improvements in bifocal lenses f0r eyeghsses and spectacles und particularly to that type 01 dass 0f lenses 0f which euch lens c'om-- prises two arts fitted accurately together und arranged so that the wearer may at will look through either part. of the lens, according t0 whether it isdesired t0 see clearly at close range 01' at a distance.

l1e primary object of the invention is the production of a lens of the character stated wherein the component parts are 0f special construction und particulzn arrangement with respect one t0 t l1e other. v

A. further object resicles in providing an auxiliary lens in connection With each lnain lens, the same to be tlll0fl(ld int0 the latte1 and a still further object resides in the provision of a beveled seat in the main lens f01' the auxiliary lens.

With these and othe1 objects in view my invention consists in tl1e novel features of construction, combination and arrangement 0f Parts, as will be hereinafter referred t0 und more particularly pointed out in the specification and claims.

In tl1e accompanying druwing forming a parl; 0f this application: Figlirel isa freut elevation of a puir of eye glasses constructed in accordance with my invention, and Fig. 2 is a detuil section as seen 0n line A--B of Fig..l.

In describing the invention I slmll refer t0 tl1e drawing, in which similar reference characters designate' corresponding p:uts 1throughout tl1e several view s, and in which designates bri lge piece 01' frmne to which 1s secured in the usnal 01' any yweferred manner, the lenses 2. Euch lens 2 l1as a sub stantxa'lly cmrular opemng armnged about centrally there1n adjacent tl1e lower edge thereof which f0rms a saut 3 f0r an auxiliary lens 4, whxch fits t here1n. Tl1e edge uf the opemng 01' seat 1s bqveled und converges 'uizoward the rear face of the lens und tl1e edge of the auxiliary lens 4 is als'o beveled co1ncident thereto.

In order to removably seat the axuiliary lens in the main lens, the peripheral edge of the former is provided With a spiral groove while the edge of the 0{ ening 01 seat has a single thread 5 formed thereon f0r engagement With the groove. must obviously be'applied from the outer face of the lens, in view of the beveled edge und when fitted in position is partially rotated, which thr6ads the same in position. It is thus capable 'of ready removal for interghangeability, butwill not become casually disengaged.

The lenses 2 und 4 may be constructed of different und they may be made variously in size with respect to 0ne another.

y constructing the device as shown und. described, to apply tl1e auxiliary lens from the front 0f the ma-in lens, the eye is not troubled by geein g the edges of the disk 01' lens 4. Since tl1e edges slope outwardly tl1e efl'ect obtained is that of plain glass, so far as theedges 0f the glass are concerned. The Vision encounters noobstruction in using a bifo zal lens constructed in accordance With thisinvention. '1he beveled seat further is found in practice to permit the lenses 4 to bemore readily and esily removed and replaced than in the ordinary forms.

From the foregoing, it will be seen that I have described wsimple, inxpensive and efiicient means for carrying out the objects of the invention and while I have particularly described the elements best adapted t0 perform tl1e functions set forth, it.is obvious that various cl1anges in form, proportion and in the minor details of construction, may be resorted to, without departing from the spirit or s acrificing any 0f the principles of the invention.

Having thus desmibed my invention, what claim is:

1. In a bifocal lens, a 1nain lens and an auxiliary lens removably applied centrzxlly adjacent the lower edge thereof.

E2. In a bifocal lens. a main lens, ancl an auxilmry lens 0f circular design romovahly applied ihereto.

3. In. a bifocal lens, a nmin lens, und an auxiliary lens 0f circulnr design rcmovubly 'Ihe auxiliary lens glass and diflerent focal lengthsapplied thereto, the edge of said latter lens being beveled inwardly.

4. In a bifocal lens a ma1n 1ens having a threaded seat therein and fan guxiliury lens 5 engaged with said seat.

5. In a bifocal lens, a main lens having a,-

seat therein, the all of which is beyeled mwardly and threaded, und an auxiliary lens having its peripheral edge beveled und th1euded for engagement with said seat.

In testimony whereof I afi'1x my signature in presence of two witnesses.

EDWIN R. TALLEY. Witnesses:

W. H. BAILEY, W. K. Sonomr. 

